Altera RapidIO MegaCore Function - Manual (Page 40)

3–4 Chapter 3: Parameter Settings
Transport and Maintenance Settings
RapidIO MegaCore Function August 2014 Altera Corporation
User Guide
Transport and Maintenance Settings
The Transport and Maintenance tab lets you enable and configure the Transport layer
and Logical layer Input/Output Maintenance modules.
Transport Layer
All RapidIO IP core variations have a Transport layer. The Transport Layer
parameters determine whether the RapidIO IP core uses 8-bit or 16-bit device IDs,
whether the Transport layer has an Avalon-ST pass-through interface, and whether
the IP core is in promiscuous mode.
Enable 16-Bit Device ID Width
The Enable 16-bit device ID width setting specifies whether the IP core supports an
8-bit device ID width or a 16-bit device ID width. RapidIO packets contain destination
ID and source ID fields, which have the specified width. If this IP core uses 16-bit
device IDs, it supports large common transport systems.
Enable Avalon-ST Pass-Through Interface
Turn on Enable Avalon-ST pass-through interface to include the Avalon-ST
pass-through interface in your RapidIO variation.
The Transport layer routes all unrecognized packets to the Avalon-ST pass-through
interface. Unrecognized packets are those that contain Format Types (ftypes) for
Logical layers not enabled in this IP core, or destination IDs not assigned to this
endpoint. However, if you disable destination ID checking, the packet is a request
packet with a supported ftype, and the Transport Type (tt) field of the packet
matches the device ID width setting of this IP core, the packet is routed to the
appropriate Logical layer.
1 The destination ID can match this endpoint only if the tt field in the packet matches
the device ID width setting of the endpoint.
Request packets with a supported ftype and correct tt field, but an unsupported
ttype
, are routed to the Logical layer supporting the ftype, which allows the
following tasks:
■ An ERROR response can be sent to requests that require a response.
■ An unsupported_transaction error can be recorded in the Error Management
extension registers.
Response packets are routed to a Logical layer module or the Avalon-ST pass-through
port based on the value of the target transaction ID field. For more information, refer
to
Table 4–4 on page 4–21 , which defines the transaction ID ranges.
Destination ID Checking
Disable Destination ID checking by default lets you turn on or off the option to
route a request packet with a supported ftype but a destination ID not assigned to
this endpoint. The effect of this setting is detailed in the
“Enable Avalon-ST Pass-
Through Interface” section.